Type 50P series is fitted in the W/T office of small sloops and gunboats and will supersede the existing sets in the second W/T office of certain capital ships and cruisers. The set will also be fitted in the second W/T offices of new construction small cruisers. It is a low/medium power set. The circuit used in the Transmitter 3U L/F has been designed to reduce, as far as possible, the frequency variations which are caused in self-excited transmitters by swaying aerials or feeder systems etc. In the earlier Type 50 sets two types of low poer tuning units were fitted, on having a frequency range of 100 to 700 kc/s and the other a frequency range of 375 to 2333 kc/s. The former was fitted with main office Type 50 sets and the latter with second office sets. The later pattern low power units have been designed to cover a frequency range of 100 to 1700 kc/s.